Collaborative Research: Nanoscale Quantitative Probing of Phase Transition in Correlated Rare-Earth Nickelates

在外部刺激下发生急剧转变的材料代表了一类新兴的半导体。 这些材料可能会影响未来的计算技术和光电设备。理解转换的微观本质对于建模其行为非常重要。在这个项目中，PI将合作探索掺杂引入的原子尺度缺陷在控制电导率中的作用，以及它在材料中的空间变化。这将是通过高空间分辨率扫描探针显微镜的组合，是敏感的导电性在纳米级和理论建模的样品中含有不同浓度的这种缺陷的导电性。除了研究，PI将参与教育和推广活动，包括吸引来自亚特兰大地区不同背景的高中生参与物理研究。过氧化镍酸盐经历绝缘体-金属转变，可以通过外部刺激如温度，压力以及生长协议进行调节。通过使用集成的高分辨率实验纳米级近场成像和光谱技术，包括红外到太赫兹，理论计算和蒙特卡罗模拟，将完成对相变的微观理解，重点是扫描探针技术。该研究将影响电子和光学材料工程和设备，基础物理和材料科学。这些结果将使人们能够在高空间分辨率下对相关氧化物的一阶相变进行基本的定量理解，并将对未来的电子学和光子学、传感、神经形态器件产生重大影响。研究和综合教育计划将促进雅典/亚特兰大地区的本科和研究生材料和纳米光电教育。整个研究的工作将为参与的学生，包括那些来自代表性不足的群体，提供先进的多学科技能，以解决具有挑战性的凝聚态/材料物理问题。该项目将包括开发新课程、本科生研究和咨询，并为来自其他机构的学生参加讲习班提供旅行奖学金。PI将把研究纳入高中物理教师/学生的教育和培训的外展活动，以及针对雅典/亚特兰大地区非洲移民学生/家庭和非裔美国青年的社区外展活动。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响力审查标准进行评估，被认为值得支持。

Materials that undergo sharp transitions in their conductivity upon external stimulus represent an emerging class of semiconductors. These materials could affect future computing technologies and opto-electronic devices. Understanding the microscopic nature of the transitions is important to model their behavior. In this project, the PIs will collaboratively explore the role of atomic scale defects introduced by doping in controlling the conductivity and how it varies spatially within the material. This will be accomplished by combination of high-spatial resolution scanning probe microscopy that is sensitive to conductivity at the nanoscale and theoretical modeling of electrical conduction in the sample containing varying concentrations of such defects. In addition to research, the PIs will participate in educational and outreach activities including engaging high school students from diverse backgrounds in the Atlanta area to participate in physics research.Perovskite nickelates undergo insulator-metal transitions that can be modulated by external stimuli such as temperature, pressure as well as growth protocols. Microscopic understanding of the phase transition with emphasis on scanning probe techniques will be accomplished by using integrated high-resolution experimental nanoscale near-field imaging and spectroscopy techniques covering infrared to THz, theoretical calculations and Monte Carlo Simulations. The research will impact electronic and optical materials engineering and devices, fundamental physics, and materials science. The results will enable fundamental quantitative understanding of the first order phase transition of correlated oxides at high-spatial resolution and will have a significant impact on future electronics and photonics, sensing, neuromorphic devices. The research and integrated education plan will promote undergraduate and graduate materials and nano-optoelectronic education in the Athens/Atlanta area. The work throughout this research will provide participating students, including those from underrepresented groups, with advanced multidisciplinary skills to tackle challenging condensed matter/materials physics problems. The project will include development of new courses, undergraduate research and advising and provide travel fellowships for students from other institutions to attend Workshops. The PIs will integrate research into outreach activities for high school physics teacher(s)/students' education and training as well as community outreach that targets African immigrant students/families and African American youth in the Athens/Atlanta area.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.